Principal Cutting Styles

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How to draw faceted stones

Brilliant cut style

In this style, the inclined facets are triangular or more or less kite
shaped. The inclined facets are shown shaded in Figure D.
The most important of the brilliant cut styles is the STANDARD ROUND
58 FACET BRILLIANT Chart-2. The crown consists of 33 facets: one table,
eight star facets, eight bezel facets, and 16 upper-girdle facets (also
known as top-half or top-break facets). The pavilion consists of 25
facets: one culet, eight pavilion facets, and 16 lower-girdle facets
(also called bottom-half or lower-break facets). The culet is sometimes
omitted, in which case the pavilion consists of 24 facets.
Figures E and F outline a simple step-by-step method of drawing the
crown and pavilion of the round brilliant. The crown is formed by
combining diagrams A through F in Figure E as follows: (A) Draw a
circle, (B) place a square in the circle, (C) place a, second square
at a 45°angle to the first square, (D)
draw lines from the points of the square to the circle, (E) draw a
light dotted tine through the center of the circle and through the
point formed by the two adjoining star facets, (F) connect the
points of the star facets with the midpoints found in Step E.

(A) Draw a circle, (B) place a cross in the circle, (C) place
another cross at a 45°angle to the
first cross, (D) draw a smaller circle inside the first circle, (E)
draw lines from the intersection of the small circle and the cross
lines to the midpoints of the are on the larger circle (these form
the pavilion facets), (F) draw the seven other pavilion facets (as
in the preceding step), erase the small center circle, and draw a
tiny circle to indicate the culet.

Step-Cut Style

This style is distinguished by the fact that one or more of the
edges of ALL of the inclined facets are parallel to the girdle edge
(Figure G). The facets are usually arranged in rows or tiers that
resemble a flight of stairs; hence the name.
The most important of the step-cut styles is the EMERALD CUT. It is
usually rectangular but is sometimes square,
in which case it is known as a SQUARE EMERALD CUT.
It has rows of elongated rectangular facets on the crown and
pavilion, parallel to the girdle, and with corner facets. Corresponding facets are usually placed on the girdle.

Combinations of the brilliant and step-cut styles are called
MIXED CUTS. By combining the outline name with the above terms, the
style of the cut may be classified; for example, a heart-shaped
brilliant-cut stone, a square step-cut stone, a rectangular mixed
cut, etc.

Cabochon Style

In contrast to faceted stones, those cut with curved surfaces are
called CABOCHONS (pronounced CAB-oh-shawn), and are classified as
follows :

Single Cabochon

This styles has a curved top and a flat base. The curved
surface may be high, medium or low.

Double Cabochon

This style has both upper and lower portions curved. It is usually
steep above the girdle-and shallow below, but may be the reverse.
Star stones, cat's-eyes and moonstones are usually cut in this
manner.

Hollow Cabochon

The hollow cabochon consists of a simple cabochon with a concave
depression in the base. Its main purpose is to lighten the color of
an otherwise too dark stone.

Lentil Cabochon

This is a comparatively thin, flat variation of the
double cabochon in which both surfaces have the same
degree of curvature. It is commonly used for opals.

Reverse Cabochon

Seldom encountered in the trade, the reverse
cabochon is a simple cabochon with a concave
depression in its top surface. It is used primarily
to produce unusual effects in star stones and
cat's-eyes.

Curved and Engraved Stones

The design of a carved gem is produced by working the entire visible
surface of the stone. The design of an engraved gem is produced by
engraving into the stone but leaving part of the surface un-worked, thus
merely providing a background for the design. The principal types are as
follows:

Cameo
A cameo is a carved gem produced by cutting away portions of the
surface above the girdle so that the entire design is ABOVE the
girdle edge. When fashioned from genuine gem materials, they are
known as STONE CAMEOS; when cut from shell, they are known as SHELL
CAMEOS; those of coral are called CORAL CAMEOS, etc. Cameos cut from
synthetic gem materials, are known as SYNTHETIC-STONE CAMEOS, and
those made from glass and other imitations are known simply as
IMITATION CAMEOS.

Intaglio (pronounced in TAL-yo)
This is a form in which the design is engraved into the stone, so
that all of the design lies below the girdle edge. Sometimes the
figure is engraved into the stone; occasionally the background is
engraved, leaving a raised figure. This type is used mainly as a
seal. Like cameos, intaglios may be
made from natural, synthetic or imitation materials.

Chevee (pronounced sheh-VAY)
The chevee is a flat-topped gemstone or other material with a large
polished oval depression in the center.

Cuvette (pronounced koo-VET)
The cuvette is a variety of chevee with a raised cameo design in the oval depression.

Scarab
A scarab is a gemstone or other substance that has been carved or engraved to represent the scarabaeus,
a beetle common to the countries bordering the Mediterranean sea.

Statutes and figurines
These are usually carved from poorer quality gem materials to represent animals,
people, leaves, flowers, temples, etc.

Pierced Carving
This type of carving is made by drilling openings through the stone, usually
as a means of removing unsightly flaws. After the flaws are removed, the drill holes are covered.

Illusion Cut
This is a novelty form of cutting and engraving. It is made by cutting a transparent material (usually
rock crystal) into the shape of a triangular block and placing grooves of various widths and
inclinations on the edge of the block. when the grooves are viewed through the opposite flat surface,
a three-dimensional effect is observed, due to reflection of the grooves from the other two surfaces,
which are inclined towards the engraved edge.

Miscellaneous Styles

Plaque (pronounced PLACK)
There are many variations of this form. The distinguishing
characteristic is two parallel surfaces, usually flat, with a
relatively narrow space between. Some have a beveled edge, although
this is not an essential characteristic. If the area between the two
parallel surfaces is quite thick, the stone is usually called a
tablet.

Bead
The bead is usually essentially spherical, with or without facets,
but is distinguished by the fact that it always has a hole drilled
through the center.

Rondelle, or Rondelle
The rondelle is similar to the bead, but consists simply of a flat
disk with a hole drilled through the center. It is generally used as
a spacer or separator between beads.

Rod
As the name implies, the rod is a cylindrical form. It is usually
used for flame-polished synthetic corundum or spinel.

Oriental or Native Cut
This term is applied principally to stones from the orient that are
characterized by a lack of symmetry and excessive weight saving.
Stones cut in this manner usually have distorted shapes,
unsymmetrical placement of facets, and other cutting faults.

Calibre or Caliber Cut
This is a term applied to small more or less rectangular stones that
are used principally to produce lines or fulfill the design of a
piece of jewelry. The resulting effect is known as CALIBRE WORK,
because the stones are often cut to a calibrated size in order to
fit the mounting. Shapes such as the keystone are used to produce
curved lines.

Melee (pronounced MILL-ee)
Melee is a term used primarily to describe small, round faceted
diamonds; however, it is also sometimes applied to colored stones of
the same size and shape.

Rose Cut, or Rosette
This is an old style of cutting that is rarely encountered except in
garnets and small diamonds. The base is hut and the top is usually
completely covered with small facets that meet at a point in the
center of the stone. Exceptions to this general rule are such cuts
as the double rose. Although rose-cut diamonds are called "diamond
chips" by those who do not recognize this style of cutting, the term
"chip" correctly applies only to small, irregular fragments that
have a variable number of haphazardly placed, irregularly shaped
facets.